PagingState<T>

Data class for managing paginated list state in ViewModels.

Module: :ui-state

Definition

data class PagingState<T>(
    val items: List<T> = emptyList(),
    val currentPage: Int = 1,
    val isLoading: Boolean = false,
    val hasMore: Boolean = true,
    val error: String? = null
)

Properties

Property	Type	Description
items	List<T>	All loaded items
currentPage	Int	Current page number
isLoading	Boolean	Whether a page is being loaded
hasMore	Boolean	Whether more pages are available
error	String?	Error message if last load failed

Operations

appendItems

Add items from a new page:

setState { copy(paging = paging.appendItems(newPosts)) }

refresh

Replace all items (pull-to-refresh):

setState { copy(paging = paging.refresh(freshPosts)) }

Example

data class FeedState(
    val paging: PagingState<Post> = PagingState()
)

class FeedViewModel(
    private val getPostsUseCase: GetPostsUseCase
) : BaseViewModel<FeedState, FeedEvent>(FeedState()) {

    fun loadNextPage() = execute(
        call = { getPostsUseCase(page = currentState.paging.currentPage) },
        onLoading = { copy(paging = paging.copy(isLoading = true)) },
        onSuccess = { posts ->
            copy(paging = paging.appendItems(posts))
        },
        onError = { copy(paging = paging.copy(isLoading = false, error = it.message)) }
    )

    fun refresh() = execute(
        call = { getPostsUseCase(page = 1) },
        onSuccess = { posts ->
            copy(paging = paging.refresh(posts))
        }
    )
}